Fish tailing/Tank slapping?

[easilyi]

Less talk more brake!

Well, I can see that this clash of wills is not gonna go anywhere if it continues on BARF, what do you gentlemen say we take this outside? Gabe, Archimedes... you guys ready to throw down the gloves (and then pick them back up so you can wear them) in an all out front/rear braking measuring war (test)? We can do emergency stops first using the front brake only and measure the stopping distance, then we'll do the same thing using both brakes and compare the stopping distances. Three riders, different skill levels, different bikes. And if anyone else wants to participate it would be perfectly welcome.

I like the idea of organized practice/testing/skill training/skill sharing/myth debunking attempts, in a safe controlled environment of course.

Just remember to try not to turn it into an ego competition and get hurt now.

I guess it will be hard to compare with three different bikes and skill levels but it's not about winning or losing, it's about learning.

 

[RhythmRider]

Looks like you answered your own question.



I'm in. Have you started another thread about it yet?

Gabe and I were in the process of selecting a venue, but I haven't heard back from him, so I dunno if it's gonna happen. Will prod him and see if he's still interested.

 

[OldFatGuy]

Gabe and I were in the process of selecting a venue, but I haven't heard back from him, so I dunno if it's gonna happen. Will prod him and see if he's still interested.

Cool. Keep me updated, please.

 

[Lovedoc]

It would be interesting to try this with one of the GPS setups like Vision Wells uses at the track. That would give you good decel data and factor out reaction time and stuff

 

[R3DS!X]

Can you say:

"ILL GET YOU HAYDEN IF ITS THE LAST THING I DO!!!!"

 

[clutchslip]

It would be interesting to try this with one of the GPS setups like Vision Wells uses at the track. That would give you good decel data and factor out reaction time and stuff

I think it is more important to do the test as a surprise stop, like in real life. These kinds of tests are done to show the effects of drinking, cell phones, etc., on driving (riding). Panic stops are going to be completely different than anticipated stops. While throwing a truck in front of our BARF test riders is probably a poor concept, throwing a flag or cardboard dummy is a decent one.

I can be the dummy, if necessary.

 

[Lovedoc]

I think it is more important to do the test as a surprise stop, like in real life. These kinds of tests are done to show the effects of drinking, cell phones, etc., on driving (riding). Panic stops are going to be completely different than anticipated stops. While throwing a truck in front of our BARF test riders is probably a poor concept, throwing a flag or cardboard dummy is a decent one.

I can be the dummy, if necessary.

interesting idea.I still think reaction times will factor. Also, you would get relative deceleration rates. Riders going to swap bikesor justrunwhut they brung.

 

[Skim325]

You should check out Doc Wong's ergonomics class. He's amazing and really helped me with my confidence while riding. His class gave me a bunch of basics, and how to adjust my body so that I'm no longer holding myself off the handlebars.

Check it out.
Docwong.com
He has a schedule up for the whole year.
Don't mean to go around advertising, but seriously. His class helped a TON. I'd recommend it to anyone.

 

[reidconti]

So you should apply maximum braking force to the front tire for an effective stop, enough to unload the back wheel and place 99 percent of the bike's weight on a dime-sized contact patch? And that gives you the best stopping distance?

Yes. Unless you'd rather put 90% of the bike's weight on the front wheel, 10% on the rear, and plow into your obstacle.

Or leave 50/50 weight distribution and don't decelerate at all before you plow into whatever's in front of you.

Hell, why not wheelie into it with 0% of your bike's weight on the front and 100% on the rear?

Under maximum deceleration, your bike's weight WILL be entirely on the front wheel. You're welcome to use your rear at this point, but all you'll be doing is stopping a spinning airborne rear wheel.

A lower rate of deceleration will allow you to use your rear brake to your heart's content. But you won't be stopping very fast. I don't get how this isn't obvious to absolutely everyone. It doesn't mean it's good practice to tell riders not to use their rear brake. But in a panic stop, your rear brake will do NOTHING, because you should already have all your weight on the front. If you don't have virtually all of your weight up front you're NOT DECELERATING FAST ENOUGH. Even using the rear brake shifts weight forward. Its effectiveness is limited by the fact that its traction is reduced as you decelerate more.

 

[RhythmRider]

I think it is more important to do the test as a surprise stop, like in real life. These kinds of tests are done to show the effects of drinking, cell phones, etc., on driving (riding). Panic stops are going to be completely different than anticipated stops. While throwing a truck in front of our BARF test riders is probably a poor concept, throwing a flag or cardboard dummy is a decent one.

I can be the dummy, if necessary.

You'd be welcome to participate. I'm gonna put up a thread about it pretty soon

 

[Gnarly Cranium]

Under maximum deceleration, your bike's weight WILL be entirely on the front wheel. You're welcome to use your rear at this point, but all you'll be doing is stopping a spinning airborne rear wheel.

I have a hard time picturing a big cruiser pulling a stoppie.

By your logic, cars should probably have their tails sticking up in the air when they stop, too.

Sure, the rear brake definitely does not do very much, and less as the weight shifts forward, but I wouldn't say it's so completely useless.

 

[Carlo]

This applies to a modern motorcycle with dual disk front brakes.
Older bikes are either less likely, or unable to pick up the back wheel with the power of the front brake.
The back tire is still unloaded, just not 100%, and it's still easy to lock up the back wheel.I'm surprised that Gabe would be questioning this.
I don't even touch my back brake in a panic situation, since I still ride British bikes with the rear brake on the left, in addition to European and Japanese bikes with the rear brake on the right. I don't like downshifting by accident when I'm trying to avoid hitting a stopped car in front of me.

Yes. Unless you'd rather put 90% of the bike's weight on the front wheel, 10% on the rear, and plow into your obstacle.

Or leave 50/50 weight distribution and don't decelerate at all before you plow into whatever's in front of you.

Hell, why not wheelie into it with 0% of your bike's weight on the front and 100% on the rear?

Under maximum deceleration, your bike's weight WILL be entirely on the front wheel. You're welcome to use your rear at this point, but all you'll be doing is stopping a spinning airborne rear wheel.

A lower rate of deceleration will allow you to use your rear brake to your heart's content. But you won't be stopping very fast. I don't get how this isn't obvious to absolutely everyone. It doesn't mean it's good practice to tell riders not to use their rear brake. But in a panic stop, your rear brake will do NOTHING, because you should already have all your weight on the front. If you don't have virtually all of your weight up front you're NOT DECELERATING FAST ENOUGH. Even using the rear brake shifts weight forward. Its effectiveness is limited by the fact that its traction is reduced as you decelerate more.

 

[Carlo]

I have a hard time picturing a big cruiser pulling a stoppie.

By your logic, cars should probably have their tails sticking up in the air when they stop, too.

Sure, the rear brake definitely does not do very much, and less as the weight shifts forward, but I wouldn't say it's so completely useless.

It's all about braking power, vehicle weight, traction and frame geometry.

Big, heavy, long motorcycles probably can't pick up the back end before traction goes away at the front. I've done panic stops on some of my vintage bikes, and never done a stoppie on one. (stopping distance is pretty bad on a couple of them, due to anemic front brake performance)

 

[reidconti]

I have a hard time picturing a big cruiser pulling a stoppie.

By your logic, cars should probably have their tails sticking up in the air when they stop, too.

Sure, the rear brake definitely does not do very much, and less as the weight shifts forward, but I wouldn't say it's so completely useless.

My car's tail would stick up in the air when panic stopping if the back end wasn't so heavy. If I could do a stoppie in my car, it would stop faster than it does now. Sadly, it cannot, so the rear brakes help the car stop a little faster than it would with no rears. (of course, they also add stability under braking)

Any vehicle that can't do a stoppie should use rear brakes the same way you use the fronts: just up to the point that you lose traction.

The bike's rear brake is useless as soon as the rear leaves the ground, because once it leaves the ground, well, you've lost traction by definition.

 

[Climber]

You probably locked up the rear tire, which would cause both fish tailing and tank slapping. I suggest you practice braking using the rear brake LIGHTLY if at all. Practice emergency stops and particularly practice NOT slamming the brakes on but increasing the pressure gradually. Even if it is an emergency, take a second to brake. It can save your life.

This.

Once you're comfortable with your emergency braking, you'll be able to moderate the pressure on your front brake lever to keep enough weight on the back wheel in order to keep it in line.

You would be best off, in a full-on must stop situation to be using maximum front brake to the point that the back brake is just about to lift off the ground but still has enough weight on it to keep tracking in a straight line. Using the rear brake would give marginal additional braking but would swing the back end around as you described.

 

[Aluisious]

I have to wonder, if pulling a stoppie is "maximum braking," how come WSBK and GP riders aren't pulling stoppies? They have light bikes and the GP guys have carbon brakes, it should be super easy for them to do it if it's so great.

I know it was just the last GP race that Dovi blamed his crash in part on problems with the rear brake. I'll put money on Dovi outbraking any BARFer.

 

[Gabe]

This applies to a modern motorcycle with dual disk front brakes.
Older bikes are either less likely, or unable to pick up the back wheel with the power of the front brake.
The back tire is still unloaded, just not 100%, and it's still easy to lock up the back wheel.I'm surprised that Gabe would be questioning this.

Exactly where did I say it's not easy to lock the back wheel? Where did I say to only use the rear brake? Where did I say that there is no weight transfer to the front? Does the front brake have more stopping power than the back? Of course it does. Can the back wheel come up off the ground under hard braking? Of course it can.

Here's what I'm really questioning here: telling new riders with no training that they shouldn't use the rear brake in panic stops. I'm also wondering how much of this "evidence" is based on actual studies, and how much of it is IES (Internet Expert Syndrome). We have one poster with what: a year of riding experience? On one bike? Holding herself out as a braking expert. That's bad, because for every one of us loudmouth over-posters, we have 100 or more riders--a lot of whom have little knowledge or experience--reading and listening to the loudest, most insistent of us. Even if we have no idea of what we are talking about.

Here's what I believe, because the MSF has tested and reviewed it for 30 years: use both brakes when you stop, every time. Apply gradual pressure to both, just short of lock-up. You practice so you get familiar with where that lock-up point is. If the back brake locks, so what: hold it on until you're stopped. If you practice maximum braking, you will shorten your stopping distance. And yes, I believe using the back brake--even if it only adds 5% of the braking power--may save your bacon in an emergency, so use it.

 

[Climber]

I have to wonder, if pulling a stoppie is "maximum braking," how come WSBK and GP riders aren't pulling stoppies? They have light bikes and the GP guys have carbon brakes, it should be super easy for them to do it if it's so great.

I know it was just the last GP race that Dovi blamed his crash in part on problems with the rear brake. I'll put money on Dovi outbraking any BARFer.

You must not have been watching WSBK last year when Spies had his rear wheel off the ground going into key corners on many of the tracks!

 

[TTTom]

It's funny to read these threads.. Nowadays If my rear tire isn't swinging back and forth I'm not enjoying myself. I'm working on consistency. You just have to roll with it; square off the corner slightly, get in the groove of the sway... wait wait wait.. TURN!

The faster the bike the more fun it is..

I've got a slipper clutch so it's kinda cheating... but I love the controlled little chirp from the tire and the ass end shake I get when I'm on both brakes and just downshift/dump the clutch.

 

[dkcwenge]

I have to wonder, if pulling a stoppie is "maximum braking," how come WSBK and GP riders aren't pulling stoppies? They have light bikes and the GP guys have carbon brakes, it should be super easy for them to do it if it's so great.

I know it was just the last GP race that Dovi blamed his crash in part on problems with the rear brake. I'll put money on Dovi outbraking any BARFer.

i think many times you'll see daylight under the rearwheel for those that brake really late / hard. i think that's why they get squiggly into the turn as they're trying to control their rear tire